Steps to reproduce the issue

This line fails
php cli/joomla.php scheduler:run -i 1 --live-site 'http://localhost:43000'

number 1 is the rotate Logs task, but it happens with any other as well

This line succeeds
php cli/joomla.php scheduler:run -i 1 --live-site 'http://localhost:43000/'

Expected result

successful run

Actual result

If you start debugging and stop on every exception, it stops with

RuntimeException: Could not parse the requested URI http://localhost:43000cli/joomla.php

in libraries/vendor/joomla/uri/src/AbstractUri.php line 367 parse($uri)

System information (as much as possible)

Tested with J5.0

Additional comments

I only found the symptoms yet, but not the root cause